kodak Tmax RS developer formula

[Drew Wiley]

Microdol is rumored to have a similar effect; but I haven't tried it. It has a different formula than Perceptol. The solvent effect is basically REVERSED at higher dilution, and grain size and definition actually increases. Allegedly "exhaustion effect", but someone else can elaborate on that. It really helps the acutance of TMX100, which has tremendous detail capacity, but poor edge acutance otherwise.

Just for the heck of it, I tried this dilution of Perceptol with ACROS a week ago, which ordinarily has both extremely fine grain and excellent edge effect, but became dramatically grainier in dilute Perceptol - opposite of classic solvent effect like D23. If applied to Delta 100, the grain becomes more conspicuous than with TMY400 in pyro. I used 1:1 Perceptol long ago for FP4 sheet film, which has nice edge effect, but soon switched to Pyro to control highlight gradation better. But at 1:3, Perceptol is a very different animal than at 1:1. And I'm certainly not the first person to notice that.

In other words, the only film I now use Perceptol for is TMX100, and only at 1:3. It's a game changer for me when it comes to medium format, because I get distinctly better shadow gradation with TMX than any other very-fine grained film currently available - the longest straight line. That's a big deal out in mountains, desert, or deep woods, where contrast can be extreme. We've discussed this before. But with large format, TMY400 and pyro is an even better option, since grain size is basically a non-issue in LF.

So I don't know what else to say, Michael - you're trying to tell the developers what to do based on hypothetical stereotypes, while I've already tested the specific distinction under question on a whole suite of films (more than those mentioned here), and even checked the real-world impact on prints at similar magnifications. I'm after practical results. And what I'm getting is quite unlike D23 results. Maybe only salt is the difference; but that's also the only difference between breakfast eggs that taste great and those that taste awful.

[Michael R]

Lol I’m not stereotyping anything.

Anyhow, since the thread is about the loss of TMax RS, it should be noted that while attaching the name TMax to these two developers was clever marketing, TMax/TMax RS were not special formulas somehow “optimized” for the TMax films. Relative to D-76 it’s simply a developer tilted more toward emulsion speed in exchange for decreased sharpness and increased graininess.

Microdol is rumored to have a similar effect; but I haven't tried it. It has a different formula than Perceptol. The solvent effect is basically REVERSED at higher dilution, and grain size and definition actually increases. Allegedly "exhaustion effect", but someone else can elaborate on that. It really helps the acutance of TMX100, which has tremendous detail capacity, but poor edge acutance otherwise.

Just for the heck of it, I tried this dilution of Perceptol with ACROS a week ago, which ordinarily has both extremely fine grain and excellent edge effect, but became dramatically grainier in dilute Perceptol - opposite of classic solvent effect like D23. If applied to Delta 100, the grain becomes more conspicuous than with TMY400 in pyro. I used 1:1 Perceptol long ago for FP4 sheet film, which has nice edge effect, but soon switched to Pyro to control highlight gradation better. But at 1:3, Perceptol is a very different animal than at 1:1. And I'm certainly not the first person to notice that.

In other words, the only film I now use Perceptol for is TMX100, and only at 1:3. It's a game changer for me when it comes to medium format, because I get distinctly better shadow gradation with TMX than any other very-fine grained film currently available - the longest straight line. That's a big deal out in mountains, desert, or deep woods, where contrast can be extreme. We've discussed this before. But with large format, TMY400 and pyro is an even better option, since grain size is basically a non-issue in LF.

So I don't know what else to say, Michael - you're trying to tell the developers what to do based on hypothetical stereotypes, while I've already tested the specific distinction under question on a whole suite of films (more than those mentioned here), and even checked the real-world impact on prints at similar magnifications. I'm after practical results. And what I'm getting is quite unlike D23 results. Maybe only salt is the difference; but that's also the only difference between breakfast eggs that taste great and those that taste awful.

[Drew Wiley]

I differ with that assessment too, Michael, and it's based not only on hard densitometer plotting of families of TMaxRS curves, but on direct conversation with certain of the people involved in its original testing. There was at that time a reason to try to obtain as even a straight line as possible. Super-XX was functionally being replaced by TMX as an allegedly better color separation film. During the R&D gestational phase of this, dye transfer was still alive, at least in the minds of one branch of Kodak. The RS version ironed out the last kink in the curve pretty well at a certain strength and temperature. Of course, most everyone forgot that feature once there was no longer a significant reason for that specific quality once it was no longer important. And once scanners and software curve controls kicked in, it became even less an issue. Only all-darkroom types like me fooled around with it for the original reason. But having done so, HC-110 proved "close enough", so there went another hypothetical RS customer. It didn't work ideally except at 75, and at that temp, I was getting edge frilling, so had to be extra careful that none of those little specks of gelatin got stuck back on the film somewhere else.

[Michael R]

There were a few reasons for the release of TMax developer, but optimization of image structure was not one of them.

[Drew Wiley]

Well, I never did use TMax RS developer to optimize image structure in any pictorial sense, but only for the specific technical lab application already mentioned. I greatly prefer pyro for field subjects. But at the time, I was mainly still shooting Bergger 200 as my primary 8x10 film, which had a better native straight line and slightly longer scale than TMax400 anyway. But it was too grainy in my opinion for 4x5 work. All of that is just retrospective now. Lots of current developer options work well for either speed of TMax, though I obviously do have certain personal preferences. I've never been a "one film / one developer" type. And even if I had been, I sure wouldn't have shelled out the unnecessary extra money for dedicated TMax RS developer.

[interneg]

I wouldn't be completely surprised if taking something like Microphen or ID-68 diluted to 1+3 (or more), and boosting the borax (etc) levels to speed it up might get into the same range as Tmax RS in useful function - at least in terms of the sharp upsweep in the highlights at higher CIs (if they relate to iodide etc placement in the slow emulsion(s)). Or ID-68 might at least give some building blocks to get started in a meaningful way.

[Drew Wiley]

No. The whole point of TMax RS, at least in its optimized sense, was to eliminate any upsweep in the curve. A truly straight line at relatively high gamma was the object, just like was possible with previous Super-XX, but with even better selective tricolor consistently, which was in fact possible. A slight kink mark at the middle of one or another of the respective curves might not bother a dye transfer kindergartner like me, but it would have caused fury with those who commercially depended on dye transfer technique in relation to superlative skintone reproduction in order to make a living. I say, "would have" because they were already infuriated about Kodak's right hand not knowing what the left was doing with respect to the future of dye transfer itself, and how certain important quality issues had already suddenly deteriorated due to generational changes at Kodak. Making these products was just as much an art as a science, and apparently the newbies tried to cut corners. It didn't affect me. I was doing Ciba. But I sure remember the squabble. It ruined the careers of certain printers, and they never forgave Kodak or trusted them again. This or that allegedly improved developer was lost in the dust storm. And dye printers could be an extremely stubborn lot, each seemingly with their own secretive formulas and techniques, and some big tempers too.

What you're describing, Interneg, can easily be achieved with D76 and TMax film. Or HC-110 provides even greater versatility. Neither will give a true straight line. But that's really only necessary in an ideal sense when making lab separations from a film original, like a chrome, and for proportionately matching masks. As long as all three RGB curves overlap, direct in-camera separations with a modest upsweep using HC-110, for example, would seem perfectly acceptable. All these applications are now so arcane that there is probably zero financial incentive to keep manufacturing a developer like RS. The last of the commercial DT operations are using scans and curve-altering software.

Most people here probably don't give a damn about the applications of TMax to color photography. But masking techniques also potentially apply to masking for sake of black and white printing, so it's useful to at least recognize analogous virtues to a particular film or developer. I find TMax 100 and HC-110 excellent for that application too, especially for smaller format original negatives, where very fine grain is a priority in masks. For LF originals, FP4 is a good masking film, but a stop slower.

[Dugan]

The lab I used to work in in the '90's used TMax RS as the general-purpose developer.

[Drew Wiley]

I'm assuming that wasn't a DT lab, Dugan. The distinction is, to get an optimal straight line, it would have to been used at high concentration, ideally one-shot, making it prohibitively expensive. I've never had a motive to try RS for general black and white film usage. Pyro addiction is hard to break. But pyro isn't a very realistic choice for high volume lab applications.

[Dugan]

The lab I worked at had Richcolor dip & dunk machines, with auto replenishment.
19 liter batches of TMax RS developer.
I was the mix guy....I ran my own negs through it, and they are holding up nicely and print well.